Predictive factors of outcome and hemorrhage after acute ischemic stroke treated by mechanical thrombectomy with a stent-retriever.

INTRODUCTION: The study attempts to identify notable factors predicting poor outcome, death, and intracranial hemorrhage in patients with acute ischemic stroke undergoing mechanical thrombectomy with stent retriever. These data could be useful to improve the selection of patients for thrombectomy.

METHODS: Patients with acute ischemic stroke treated with the Solitaire FR device were retrospectively analyzed from a prospectively collected database. We assessed the effect of selected demographic characteristics, clinical and imaging factors on poor outcome at 3 months (modified Rankin score 3-6), mortality at 3 months, and hemorrhage at day 1 (symptomatic and asymptomatic).

RESULTS: From May 2010 to April 2012, 59 consecutive patients with an acute ischemic stroke underwent mechanical thrombectomy. At 3 months, 57.6% of the patients were functionally independent (modified Rankin Scale 0-2) and mortality was 20.4%. Multivariate analyses revealed that a thrombus length > 14 mm (p = 0.02; OR 7.55; 95% CI 1.35-42.31) and longer endovascular procedure duration (p = 0.01; OR 1.04; 95% CI 1.01-1.07) were independently associated with poor outcome. A higher baseline Alberta Stroke Program Early CT (ASPECT) score (p = 0.04; OR 0.79 per point; 95% CI 0.63-0.99) and successful recanalization (p = 0.02; OR 0.07; 95% CI 0.01-0.72) were independent predictors of good functional outcome. Baseline ASPECT score (p < 0.01; OR 0.65; 95% CI 0.54-0.78) independently predicted symptomatic intracranial hemorrhage at day 1.

CONCLUSION: Absolute baseline ASPECT score reflects early symptomatic hemorrhage risk and functional outcome at 3 months. Thrombus length measured on MRI play an important role on functional outcome at 3 months after thrombectomy. Further analyses are needed to determine its importance in the selection of patients for mechanical thrombectomy.